The present invention relates to damping vibrations in mounting vibration-prone devices, such as fans or other devices with moving parts, and more particularly relates to a mount relying on a spring to prevent transmission of vibrations including sounds from a vibration-prone device to a surrounding structure.
Many types of equipment include both components that cause vibrations and components that are sensitive to vibrations. One example is scientific equipment containing sensitive transducers as well as heavier components such as vacuum pumps. Other sensitive measuring devices may be associated with computer processors that require cooling fans. Attempts have been made to isolate fan vibrations by suspending the fan from a network of coil springs, as shown in U.S. Pat. No. 5,308,224, or by hanging the fan on a cantilever beam.
The need to isolate computer cooling fans to prevent vibration and attendant housing structure vibration noise, is recognized in U.S. Pat. No. 5,208,730. However, a complex resilient mounting apparatus is described to address the problem.
A cordless or cellular telephone powered by a fan-ventilated metal-air battery presents a difficult challenge because the components must be very small and also must not produce noise that would interfere with a conversation over the telephone. Space within the apparatus cannot be spared for spring suspension systems.
Thus, there has been a need in the art for a simple, inexpensive vibration damping mount, useable with miniaturized electronic components, and capable of effectively preventing vibration and noise without occupying any significant space.
The present invention seeks to provide a vibration damping mount capable of minimizing vibration and noise while minimizing the space it occupies. The invention also seeks to provide a vibration damping mount suitable for use with hand held electronic devices.
These objects are accomplished by providing a mount that includes a spring shaped to support the vibration-prone device and damp its vibrations. The mount can be shaped to adapt to the device it is holding and to the surrounding hardware for the purpose of minimizing the space it occupies.
Generally described, the present invention provides a damping device for mounting a vibration-prone device to a structure, comprising a retainer shaped to receive the vibration-prone device; a spring extending from the retainer in an arc, the spring being held to the structure at a location spaced along the arc from the retainer. In selecting a particular structure for the spring, many variations are possible. The arc may be smooth or may be a plurality of connected discrete segments. Preferably, the arc is shaped to turn through at least 180 degrees. In some applications a full turn or multiple turns will provide optimal support and damping.
In a preferred embodiment, the spring is a spiral, the turns of which may lie generally in one plane. In the alternative, the turns may lie on a three dimensional shape such as a cone, hemisphere, or pyramid. The planar spring mount is space efficient. The spiral may comprise wire shaped at the center of the spiral to receive a part of the mounted device. Also, an outer turn can be shaped to be received in a peripheral groove provided by the structure. For example, when the vibration-prone device is a fan, a mandrel from the central stator member of the fan may be held in a winding at the center of the spiral, and the spiral may be positioned in an opening in a wall of a housing with the outer turn fitted in a groove in the opening. With the spiral mount thus generally coplanar with wall of the housing, and positioned in the opening required for air supply to the fan, little or no additional space is needed for the mount.
The present invention further contemplates a ventilation system including a fan mounted on a damping device as described above, and a metal-air cell housing including a fan mounted on a similar damping device. The present invention is particular useful in cellular telephones where noise due to vibration is undesirable.
According to another aspect of the invention a vibration-damping fan mount is provided, comprising a support member having a thickness and defining therethrough an opening having a peripheral wall; and a spiral spring defining a central fitting shaped to engage a portion of a fan and an outer turn shaped to engage the peripheral wall of the opening. The peripheral wall of the opening may optionally define a groove, and the outer turn of the spiral spring may fit into the groove. Preferably, the groove encircles the peripheral wall, and the outer turn forms a loop that resiliently snaps into the groove.
According to another aspect of the invention, a damping device for mounting a vibration-prone device to a structure is provided, comprising a retainer shaped to receive a vibration-prone device; and a spring extending from the retainer in a figure, the spring being held to the structure at a location spaced along the figure from the retainer, and the shape of the figure between the retainer and the structure allowing resilient motion in at least two orthogonal directions. In a preferred embodiment, the resilient motion allowed by the spring is omni-directional.
Other objects, features, and advantages of the present invention will become apparent upon review of the following description of embodiments of the invention, when taken in conjunction with the drawings and the appended claims.